The particular field of application of the invention is routers having a downwardly projecting routing or milling bit with means for drawing off dust produced by it.
Such a router has been described in the said application Ser. No. 601,636. It is made up of a downwardly facing router guide through which the router bit projects in a downward direction. The guide is in the form of a hollow body opening towards the router bit. Its internal space is in communication with the a vacuum connector for drawing off the chips etc. through a suction line. The downwardly projecting router bit may be provided with a chip collector to protect the user against the flying chips as they are thrown tangentially to the side by the router bit.
This previusly proposed chip collector is not fully satisfactorily adapted for use with the dust abstracting system so that trapped chips are, if anything, only swept along by the aspirated air current to a small extent and some chips are left and have to be removed by hand, something that wastes time and may even be dangerous if carried out when the router bit is still running. This prior patent application does not completely fulfill its aim of making possible routing in a dust-free atmosphere.